| 主权项 |
1. A gas phase olefin polymerization process wherein the process comprises adding a seed bed to a gas phase reactor prior to performing a polymerization reaction, wherein the seed bed comprises a polyethylene polymer which is produced by polymerizing ethylene and optionally an alpha olefin in a reactor with an olefin polymerization catalyst comprising: i) a phosphinimine catalyst; ii) an inert support; iii) a cocatalyst; and iv) a catalyst modifier; wherein the catalyst modifier is present in from 0.25 to 6.0 weight percent based on the weight of i), ii) and iii) of the polymerization catalyst and comprises a compound having the formula: R1R2xN((CH2)nOH)y where R1 is a hydrocarbyl group having from 5 to 30 carbon atoms, R2 is hydrogen or a hydrocarbyl group having from 1 to 30 carbon atoms, x is 1 or 0, y is 1 when x is 1, y is 2 when x is 0, each n is independently an integer from 1 to 30 when y is 2, and n is an integer from 1 to 30 when y is 1; provided that the polyethylene polymer comprises at least 1 ppm of the catalyst modifier (based on the weight of the polyethylene polymer) which was originally present in the olefin polymerization catalyst. |
